A coronary artery bypass graft (CABG) procedure is a common surgical procedure in which a graft vessel, such as a saphenous vein or mammary artery, is connected surgically to two target vessels. Traditionally, the diameter of the aorta, the diameter of the graft vessel, and the wall thickness of the graft vessel are not measured during CABG surgery. Instead, the surgeon visually inspects the diameter of the aorta and the diameter of the graft vessel, and disregards the wall thickness of the graft vessel. While such inspection may be adequate for suture-based anastomosis on a stopped heart, it may be inadequate when anastomotic connectors and deployment systems are used.